Our family GP, is advising people to opt out My Health Record.
He gives the example of having a stubby or two, on a Saturday afternoon and then having a minor accident while doing an oil change on your trusty ute. You finish up in accident and emergency requiring a few stitches in your hand, what happens if it gets written on your health record that you presented at hospital in an agitated state, covered in blood, a few bruises etc.
Bit awkward if it gets written up by some ward clerk, nurse that you arrived at hospital in agitated state because you are a drug user, or heavy drinker or whatever.
Plenty of people will be eager to see or have an interest what is on your health record- from private health insurance, car insurance, travel insurance, life insurance or even down to your bank for a business or home loan.